Intaglio printing-plate



J. A. COREY.

INTAGLIO PRINTING PLATE.

APPLICATION mm 050.24. 1914.

1,339,741 Patentbd May 11, 1920.

Inventor d. 6-21 y w E'IW I fltiomey.

the followingis a. specification.

:rmEsALBEnT COREY, or LONDON, ENGLAND.

mTAGLIo PRINTIN -PLATE.

. Specification of Letters Patent. Patented 11 1920.

Application filed December 24, 1914. Serial No. 878,978.

To all whom it may conccm:

Be it known that I, JAMEs ALBERT Comer, a subject of the King of Great Britain and Ireland, residin at 18 Manor Mansions, Belsize Grove, ampstead, London, N. W.,

England, have invented certain new and useful Intaglio Printing-Plates, of whic This invention relates to printing by the use of intaglio printing surfaces.

The advantages of intaglio printing surfaces for the effective reproduction of illustration is Well known. Such printing surfaces have long since been used for printing in flat-bed printing machines and more recently in rotary printing machines; but their general use for printing in rotary machines is hindered and their utility restricted generally by the difiioulty of curving the printing plate without distortion 0r stretch ing of the design or image in one direction.

This difliculty alone precludes the employment of rotary printing machines in printing from existing plates, intended for use flat, and carrying designs and'images ,that must be printed with a -fine degree of accuracy as to size and proportions-such as ordnance survey maps in one or more colors, postage stamps, or pictures in colors. It is also impracticable to engrave such work on plates so thin that they can be bent without distortion and at the same time be suitable for reproduction by electrotyping.

One of the objects of the invention is thus to render practically possible the duplication of all such fiatintaglio or photogravure plates of ordinary thicknessin a manner that will permit of curving without distortion.

The invention consists of an intaglio printing surface produced in the form of a thin film or plate by electrodeposition. Such a' fihn or plate can be used without any backing or support and can be curved Without the printingface appreciably stretching so that thus it may be applied upon a cylinder or cylindrical frame in a rotary print-- ing machine and used for printing whereby perfect register is secured.

The invention is diagrammatically illustrated in the accompanying drawings in which;-

Figure 1 diagrammatically represents an intaglio printing surface produced according to the invention, and

Fig. 2 diagrammatically illustrates a plate cylinder upon which the intaglio printing surface Fig. 1 may be mounted. V

I prepare such films or plates by first producing an original intaglio surface in the fiat by any known method, and I' then take from the surfacea mold in lead or other soft metal or suitable material for the production of a matrix. e

The matrix thus produced is used for the production of such films or plates by electrotyping. The electro-type film or plates,

however, is deposited by the use of a high current density so as thus to secure a dense, hard and regular, deposit of metal and so as thus to produce a thin .film or a thin plate which may be subjectedto friction'in the wiping or scraping of the surface and to the strain imposed during impression without excessive Wear and without the possibility of deformation.

I advantageously make first of all upon the matrix a thin deposit of nickel and I then complete the film by the deposit of copper. Any other hard surface may, how- :ver, be first electrodeposited upon the marix.

In-carrying the invention into effect according to one method I advantageously employ strips of sheet lead for making the matrices, andthe'se I produce by pressing the lead sheets in contact with the original intaglio engravedvsurface in any hydraulic press at a pressure of about ton to 2 tons to the square inch. I interpose between the lead sheet and the press a soft resilient layer which may be formed ofv a numsoft resilient layer gradually decreases inthickness or in the number of layers on each side of the part at which the engraved surface occurs, so that thus't-he lead mold produced has no 'lines formed upon it nor unevenness of surface, and I effect the molding so that no injury will result to the surface of the original.

The matrix produced will thus be of dimensions corresponding to those of the finished electrotype, or it may be cutdown exactly to correspond, the surface being smooth at those parts towhich the image does not extend.

The matrix is then used for the production of an electrotype plate or sheet in the use of a current of high density. The elec- "her of sheets of a suitable material which trolyt'e is maintained in circulation and its specific gravity or degree of concentration maintained uniform as far as practicable so as thus to insure a hard, dense and regular deposit of metal. I prefer to electro-deposlt a thin surface of a hard metal, such as nickel and I produce a film of about one-fortieth of an inch in thickness.

Such a film will have its surface smooth where the image does not extend.

The film or thin plate thus produced ma be bent around the plate cylinder 1) (Fig. 2 and mounted thereon upon a cylindrical bend in which position it may be fixed, for example, by having its upper and lower edges clamped and by having its edges and the Whole of its surface supported upon the cylinder, so that thus a truly cylindrical surface is presented for impression, which may be effectively wiped or scraped.

It Will'be understood that the electrotype films or thin plates such as a thus produced having the image in determined positions thereon and the smooth surfaces Where required extending beyond, may be fitted into position in any suitable manner, and they may be produced in any number and of any particular Width. It will, however, be understood that thus the image 0 (Fig. 1) may be co-extensive or nearly so with the plates or films. Further it will be understood that by the provision ofa thin film or sheet as described it is unnecessary for it to be deformed in its application upon the cylinder or if at all only to a slight extent,

as it readily bends to the extent that is necessary.

I provide the plate-carrying cylinder such as b of relatively large diameter, so that if.

necessary a circular series of films or thin plates may be mounted thereon, or the films or thin plates may be mounted in particular position on the cylinder '6 so that, for example, an eight paged sheet or any other size of sheet may be printed in a single rotation of the plate-carrying cylinder For example, one page plate may be mounted upon one quarter of the periphery of the platecarrying cylinder within a suitable recess and seating provided for the purpose, While the other three plates may be mounted in corresponding peripheral positions on the cylinder, which may beof two, four or other pages in width and thus have a plate carry- JAMES ALBERT COREY. Witnesses i R. 0. HUe1sms, O. J. WORTH, 

